Rock drilling mechanism



Feb. 15, 1938. E. G. GARTIN ROCK DRILLING MECHANISM Filed Jan. 4, 1956 4 Sheets-Sheet l @Hub Feb. 15, 1938. E, C;-- GARTlN l 2,108,058

ROCK DRILLING MECHANISM Feb. i15, 193s.

E. G. GARTIN 2,108,058

ROCK DRILLING MECHANISM I Filed Jan. 4, 1936 4 Sheets-Sheet 3 imn/fam. EZmef 6T @afn .Il Ill Feb. 1'5, 1938. E G. @Amm 2,108,058

ROCK DRILLING MECHNISM Filed Jan. 4, 1956 4 Sheets-Sheet 4 vist Patented Feb. 15, 1938 UNITED STATES PATENT OFFICE Elmer G1. Gartin, Claremont, N. H., assigner to Sullivan Machinery Company, a corporation of Massachusetts Application January 4, 1936, Serial No. 57,563

25 Claims.

This invention relates to rock drilling mechanisms, and more particularly has reference to improvements in the feeding mechanism of a rock drill of the mounted type and improved support- '5 ing, adjusting and guiding means for the drill.

An object of this invention is to provide an improved rock drill feeding mechanism whereby with an extremely compact construction a relatively long range of feeding travel of the drill is attained. Another object is to provide an improved supporting and guiding means associated with the feeding mechanism for supporting and guiding the rock drill during the feeding operation. A further object is to provide an improved rock drill feeding mechanism of the pressure iiuid actuated cylinder and piston type wherein a plurality of coasting cylinders and pistons are employed, together with improved means .forcontrolling the supply of pressure fluid to the various cylinders. A still further object is to provide .an improved rock drill feeding mechanism of the multi-cylinder type wherein one of the cylinders may be employed as an adjusting cylinder for positioning the rock drill with respect to the work prior to the operation of the other cylinders of the feeding means and having embodied therein means for locking the piston of the adjusting cylinder in adjusted position during the feeding Yoperation. A further object is to provide an improved adjustable supporting structure for a rock drill. These and other objects will, however, hereinafter more fully appear.

In the accompanying drawings there are shown for purposes of illustration two forms which the invention may assume in practice.

these drawings,

Fig. l is a plan view of one illustrative form of the invention.

Fig. 2 is 'a view in longitudinal section taken substantially on line 2 2 of Fig. l, the rock drill being shown in side elevation.

Fig. 3 is a longitudinally extending horizontal sectional view taken substantially on line 3 3 of Fig. 2.

Fig. 4 is a cross sectional View taken on line Q fi of Fig. 2.

Fig. 5 is a cross sectional view taken on line 5 5 of Fig. 2.

Fig. 6 is a longitudinally extending horizontal sectional view taken substantially on line 6 6 of Fig. 2.

Fig. '7 is a detail sectional view taken on line 'I 'l of Fig. 6.

Fig. 8 is a detail sectional View taken on line 8 8 of Fig. 6.

Fig. 9 is a cross sectional view taken on line 9 9 of Figs. 2 and 8.

Fig. 10 is a horizontal sectional view taken on line Ill-l0 of Fig. 8.

Figs. l1, 12 and 13 are detail sectional views taken on lines H I l, I2 I2 and I3 I3 respectively, of Fig. 6.

Fig. 14 is an end elevational view of the mechanism shown in Fig. 2, with the rock drill removed.

Fig. 15 is a fragmentary sectional view taken in the plane of Fig. 7, showing the valve in a different position.

Fig. 16 is a fragmentary sectional view taken in the plane of Fig. 8, showing the valve in a different position.

Fig. 17 is a yView similar to Fig. 2 showing a modified form of the invention.

Fig. 18 is an enlarged fragmentary View in longitudinal section taken in the plane of Fig. 17.

Fig. 19 is a cross sectional view taken on line l9 |9 of Fig. 17.

Fig. 2O is a detail sectional view taken substantially on line 20 20 of Fig. `19.

Fig. 21 is a detail sectional view taken on line 2| 2I of Fig. 19.

Fig. 22 is a detail sectional view taken on line 22 22 of Fig. 19.

Fig. 23 is a detail sectional View taken in the plane of Fig. 20, showing the neutral position of o the reversing valve.

Fig. 24 is an enlarged cross sectional view taken on Vline 24 24 of Fig. 17.

Fig. 25 is an enlarged horizontal sectional view taken substantially on line 25 25 of Fig. 17.

i Fig. 26 is an enlarged horizontal sectional view taken on line 2(5 26 of Fig. 17.

In the illustrative embodiment of the invention shown in Figs. l to 16, inclusive, I designates a hammer rock drill of a conventional design, the improved drill feeding means is generally designated 2, and 3 generally designates the drill guiding means.

The hammer rock drill is of the pressure fluid actuated type comprising a motor cylinder 4 have ing a rear head 5 and a front chuck housing t, the motor cylinder containing a reciprocatory hammer piston for delivering impact blows to the shank of a usual drill steel l supported within the chuck housing.v The drill motor is provided, in a usual manner, with a suitable pressure fluid supply connection and throttle valve mechanism.

The feeding means 2 comprises a stationary feeding or adjusting cylinder 8 having an integral bottom trunnion support or swivel plate 9 adapted to be clamped in a known manner in the saddle mounting of a suitable drill support. Contained in the cylinder 8 is a reciprocable piston I5 having a piston rod II extending rearwardly through the packed rear head I2 of the cylinder, and this rod is xed at I3 within a -depending projection I4 formed integral with the rear head block I 5 of a reciprocable feed cylinder I5. The cylinder I6 is rigidly secured through the head block I5 to the piston rod II and arranged parallel with the stationary cylinder 8, and contains a reciprocable feed piston I'I having a piston rod I8 extending forwardly through the packed front head I9 of the cylinder I 6. The piston rod I8 extends forwardly through the packed rear head 25 of a reciprocable feed cylinder 2l alined with the feed cylinder I6 and reciprocable with respect thereto. Contained in the cylinde-r 2l is a feed piston 22 fixed to the forward end of the piston rod I8. The cylinder 2l has a front head block 23 formed with depending arms 24, 24 to which are secured at 25 elongated parallel guide rods 26, 26 of the guiding means 3. These guide rods extend rearwardly longitudinally along the opposite sidesI of the stationary cylinder 8 and are guided for reciprocation within elongated guides 21, 21 projecting laterally from the opposite sides of the stationary cylinder 8. As shown most clearly in Figs. 3, 4 and 5, the cylinder I6 has parallel guides 28, 28 depending from the opposite sides thereof and slidably engaging the parallel guide rods 25, 25. It will thus be seen that the cylinder ZI is supported and guided by the parallel guide rods 26, 25 for sliding movement therewith with respect to the. stationary cylinder 8, while the cylinder I6 is slidably guided for longitudinal movement along the guide rods 26, 26.

The rock drill I is preferably detachably mounted on the feed cylinder 2| for movement therewith and the mounting means for the rock drill, in this instance, comprises an upstanding lug 29 integral with the rearward portion of the cylinder, and having lateral perforated arms 38, and a depending lug 3l on the drill head 5 projects down between the arms and is held thereon by a holding bolt 32 passing through the perforations in the arms and lug. Upstanding projections 33 formed on the cylinder 2l in advance of the lug 3l and straddling the sides of the rock drill carry clamps 35.# for engaging projections on the drill for securing the drill down on the cylinder. By releasing the holding bolt 32 and the clamps 35 the rock drill may be readily dismounted from the feed cylinder.

Now referring to the means for supplying and controlling the flow of pressure fluid to the cylinders, it will be noted that arranged in a transverse bore 35 formed in a lateral boss 36 integral with the upper forward surface of the feed cylinder I5 is a rotary control valve 31 having an operating handle 38. Pressure fluid is adapted to be supplied to a pressure chamber 39 formed internally within the valve through a suitable pipe connection @il from, any suitable pressure fluid source. A passage 4I communicating with the valve bore and connectible by a passage 42 in the valve with the pressure chamber 39 cornmunicates through a port 43 with the rear end of the bore of the cylinder I6. A passage 44 communicable through the passage 42 in the valve with the pressure chamber 39 leads to the forward end of the bore of the cylinder I5. When the valve 3l is in the position shown, the passage 42 communicates with the passage 4I,

while the passage 44 is connected through a circumferentially extending groove 45 on the valve with a vent passage 46. When the valve 37 is in its opposite position, the passage 42 communicates with the passage 54 while the passage 4I is connected to the vent passage A5 through the groove 45. The rear end of the bore of the cylinder I5 at the rear side of the piston lli is connected to the forward end of the bore of the cylinder 2| at the forward side of the piston 22 through a passage 4'! extending longitudinally through the piston rod I8, while the forward end of the bore of the cylinder I5 at the forward side of the piston I 'l and the rear end of the bore of the cylinder 2l at the rear side of the piston 22 are connected by a passage 48 in the piston rod. Formed in the rear head block I5 of the feed cylinder I6 is a bore 49 containing a rotary control valve 50 having an operating handle 5I, and when this valve is in the position shown in Figs. 2 and 7, the passage il is connected through a circumferential groove 52 on the valve 55' with a passage 53 communicating with a longitudinal passage 54 formed in the piston rod II and leading to the bore of the cylinder 8 at the rear side of the piston i8. The bore of the cylinder 8 at the forward side of the piston I is connected by a longitudinal passage 5S in the piston rod II to a passage l in the rear head block I5 (see Fig. 7). This passage 5l is communicable through a circumferential groove 58 on the valve 5D with a passage 59 in turn communicable through a longitudinal groove 60 in the wall of the valve bore 36 (Figs. 11, 12 and 13) with the circumferential groove 45 communieating with the vent passage 48. It will thus be seen that when the valves 3l and 55 are in the position shown in Fig. 2, pressure iiuid may ilow from the central valve chamber 3S through passage 42 in the valve, passage 42, groove 52 in the valve 55 and passages 53 and 54 to the bore of the cylinder 8 at the rear side of the feed piston I Il to effect forward feed of the piston l0 with respect to the cylinder 8, the forward end of the bore of the cylinder 8 at this time being connected to exhaust through passages 58 and 5l, groove 58, passage 59, groove 5! in the wall of the valve bore 35, groove 45 and vent passage 45. When the position of the valve 5l is reversed, the passage 4I leading to the rear end of the bore of the cylinder 8 is connected to exhaust through groove 45 and vent passage 46, while the passage 59 leading to the forward end of they bore of the cylinder 8 is connected with the pressure chamber 39 in the valve 37 through passage 52 and longitudinal groove 55 in the wall of the valve bore 36.

The supply of pressure fluid to and the exhaust of fluid from the feed cylinder 8 may be controlled by the valve 58 independently of the valve 3l, and the means for accomplishing this function comprises a passage 55 arranged parallel with the passages 4I and 55) therebetween communicating constantly with the pressure chamber 39 in the valve 3l' through a circumferential groove 65 on the valve connected by a passage 6l with the pressure chamber 39. The passage 55 is communicable through a circumferential groove 58 on the valve 55 with bly-pass passages 69 and 'i8 communicating, as shown in Fig. 1G, with the passages 5i and 53 respectively. The passages 69 and 'l5 are connectible by a circumferential groove "il on the valve 5E with a vent passage l2. When the valve 55 is in the position shown in Fig. 8, communication of the supply passage 65 with the passages 69 and 10 is cut olf, and when the valve 5D is turned into the position shown in Fig. 15 communication of the passages 4I and 59, through the grooves 58 and 52, respectively, on the valve 58 with the passages 51 and 53 is cut off by the valve 50, while the passage 65 communicates with the passage 1I) through the groove 68 on the valve 50. At the same time the passage 69 is connected to the vent passage 12 by the groove 1I. When the valve 58 is in this position, pressure fluid may ow from the pressure chamber 39 in the valve 31 through passage 51, groove E5, passage 65, groove 68 on the valve 50, passage 18, passage 53 and passage 54 in the piston rod II communicating with the bore of the cylinder 8 at the rear side of the feed piston I0, thereby to effect lforward feed of the piston with respect to the cylinder, the forward end of the bore of the cylinder 8 being connected to exhaust through passage 56 in the piston rod Il, passage 51, passage 89, groove 1I on the valve 50 and vent passage 12. When the valve is turned into its position reversed from that shown in Fig. 16, the passage 65 is connected through the groove 68 on the valve 58 with the passage 69 communicating with the passage 51 leading to the bore of the cylinder 8 at the forward side of the feed piston I9, while the rear end of the feed cylin- 'der bore is, connected to exhaust through passage 53, passage 18, groove 1I on the valve 5I! and the vent passage 12. It is accordingly evident that feed of the feed piston I 8 is either forwardly or rearwardly with respect to the feed cylinder 8 and may be controlled by the valve 58 wholly independently of the valve 31.

When the feed cylinder 8 is utilized as an adjusting cylinder for positioning the rock drill with respect to the work prior to the feeding operation, it is desirable to hold the feed piston i8 in its stationary adjusted position with respect to the cylinder 8 after such adjustment of the rock drill with respect to the work has been made. To accomplish this function a clamping device 18 is provided for gripping the piston rod II to hold the feed piston I8 against movement with respect to the cylinder 8. This cl-amping device comprises a split clamp having a tightening bolt 1d and threadedly secured within the rear head I2 of the feed cylinder S. In this, instance, the clamp threaded within the cylinder head I2 forms a means for compressing the packing of this head into tight sealing engagement with the piston rod II.

The general mode of operation of the form of the invention above described will be clearly apparent from the description given. When the feeding means is collapsed, the rock drill I assumes its rearmost position, as shown in Fig. 2. When the parts yare thus disposed and it is desired to move the rock drill into its operative drilling position with respect to the work prior to the feeding operation, the operator rotates the valve 58 into its position to supply pressure fluid to the bore of the cylinder 8 at the rear side of the feed piston I8, thereby causing the latter to move forwardly with respect to the cylinder 8. When the rock drill I is in the desired adjusted position with resp-ect to the work, the operator tightens the bolt 1li to bring the clamp 13 into tight engagement with the piston rod I I to lock the feed piston Il) against movement with respect to the feed cylinder 8. The operator then rotates the control valve 31 into the position shown in Figs. 2 and 11, thereby to supply pressure fluid to the rear end of the bore of the cylinder I6 at the rear side of the feed piston I1, and through the longitudinal passage 41 in the piston rod I8 to the forward end of the bore of the cylinder 2| at the forward side of the feed piston 22, and `as a result, the feed cylinder on which the rock drill I is mounted is fed forwardly with respect to the feed piston 22, while the feed piston I1 is fed forwardly with respect to the feed cylinder I6, thereby feeding the rock drill forwardly with respect to the feed cylinder 8. During this forward feeding movement, the rock drill and the cylinder 2I are guided by the guide rods 26, 26 engaging the guideways 21, 21 on the feed cylinder 8. When the position of the control valve 31 is reversed, pressure fluid is supplied to th-e forward end of the bore of the cylinder I6 at the forward side of the feed piston I1 and through the passage 48 in the piston rod I8 to the rear end of the bore of the cylinder 2I at the rear side of the feed piston 22, and as a result, the feed piston I1 is fed rearwardly with respect to the feed cylinder I6 and the feed cylinder 2I is fed rearwardly with respect to the feed piston 22, thereby moving the rock drill into its retracted position. If desired, the clamping device 13 may be released and the feed cylinder 8 utilized in conjunction with the cylinders I6 and fI to obtain a triple feed, soI that when pres.- sure fluid flows to the cylinders IB and 2I to effect drill feed, pressure fluid at the same time ows to the third feed cylinder 8.

In the modified form of the invention shown in Figs. 17 to 26, inclusive, there is shown a rock drilling mechanism of the so-called tower mounted type generally comprising a frame 15 mounted on a pair .of Wheels 16 and adjustably secured by a clamp 11 to the wheel axle 18. Pivotally connected to the frame 15 is a leg 19 having an adjustable ground engaging point 80. As shown in Figs. 17 and 25, the frame 15 is provided with a circular flange 8| on which is rotatably mounted a tubular column or standard 82, the standard having a lateral lug 83 having an opening adapted to register with openings 84 formed in the circular flange 8l, a through bolt 85 passing through the openings in the lug and flange to hold the column in its adjusted position about its axis with respect to the circular flange 8|. Formed in the column 82 is a feed cylinder bore 86 containing a reciprocable feed piston 81, the latter having a piston rod 88 extending upwardly through the packed upper head 89 of the feed cylinder. The upper end of the piston rod 88 is secured at 98 within a transverse connecting frame 9! in turn secured at 92 to the upper end of a piston rod 93 herein arranged parallel with the feed piston rod 88. In this instance, the upper portion of the column above the cylinder head 89 is longitudinally slotted to receive the transverse frame 9|, when the feed piston assumes its forward position within the feed cylinder bore. The piston rod extends downwardly forwardly through the packed rear head 94 of a feed cylinder 95 herein secured tothe rear head block of a rock drill generally designated 96 herein similar in design to that disclosed in Figs. l and 2. Contained in the bore of the feed cylinder 95 and secured to the forward end of the piston rod 93 is a feed piston 91. The rock drill is secured to a guide member 98 having a circular guiding surface 99 slidably engaging an exterior surface of the tubular column 82. The column has a longitudinal key |89 engaging the side edges of a split clamp IDI formed on the guide for preventing rotative movement of the guide with respect to the column. The clamp lill has a clamping bolt EQ2 whereby the clamp may be tightened to secure the guide 953 in any desired adjusted position respect to the column 2. Mounted in the upper portion of the column above the packed feed cylinder head 89 is a ring clamp S having a clamping nut me for clamping the piston rod Sii to the column, thereby to lock the feed piston 87 in any desired adjusted position with respect to the feed cylinder 86. Mounted on the upper end of the feed cylinder is a split clamp H95 for clamping the piston rod 93 to the cylinder, thereby to hold. the feed piston 9i in any desired adjusted position with respect to the feed cylinder.

Now referring to the improved means for supplying pressure uid to the feed cylinders to effect fee-1i of the root: drill with respect to the column 32, it will be noted that mounted in a transverse bore H36 within the rear head block of the rock drill 96 is a rotary control valve i'i having an operating handle itt. This valve has an internal pressure chamber E69 communicating through a pipe connection H with any suitable source of pressure fluid supply. The pressure chamber ifi communicates through a passage il?, with a circumferential groove il@ on the valve. A circumferential groove H5 on the valve communicates with a vent passage l i6. Leading from valve bore ii'it is a passage l i'i communi-- cat-ing with a bore H3 in which is mounted a rotary reversing valve iig. The passage ill is communicable through a groove 23 in the valve iid with a passage l2! leading to the bore of the cylinder 95 at the forward side of the feed piston Si. Communicating with the valve bore it@ (see Fig. 20) is a passage |23 parallel with the passage iii and communicating through a groove i2@ in the valve H9 with a passage 21 leading to the rear end of the bore of the cylinder @E at the rear side of the feed piston 9i. When the valve ill is turned to the left from the position shown in Fig. 20, pressure fluid may flow from the pressure chamber lli@ in the valve through passage iid, groove lid, passage ii'i, groove 23 in the valve H9 and passage i2! to the forward end of the bore of the cylinder S5 to effect feed of the rock drill with respect to the column t?, the rear end of the bore of the cylinder 35 being connected to exhaust through passage 827, groove i2@ in the valve M9, passage 23, groove H5 in the valve iiil and vent passage i It. The forward end of the bore of the cylinder 95 is connected through a passage i223 in the piston rod 93 with a transverse passage i3@ in the connecting frame iii in turn communicating through a passage iili in the piston rod 83 with the rear end of the bore of the cylinder 86 at the rear side of the feed piston 3l. The forward end of the bore of the cylinder Bti at the forward side of the feed piston 3' is connected through a passage i32 in the piston rod SB with a transverse passage i553 in the connecting member Si, the passage H33 in turn communicating through a passage |34 in the piston rod Si? with the rear end of the bore of the cylinder 95 at the rear side of the feed piston il'i. It will thus be seen that whenever pressure fluid is supplied to one end or the other of the bore of the cylinder 95, pressure fluid is at the same time supplied to one end or the other of the bore of the cylinder 8E. By reversing the position of the reversing valve H9 the flow of' pressure fluid to the cylinder 35 may be reversed wholly independently of the control valve lill. When the reversing valve is in the position shown in Fig.

2,108,058Y Y Y Y 23, supply of pressure fluid to both ends of the feed cylinder is cut off.

The general mode of operation of the modified form of the invention shown in Figs. 17 to 26, inclusive, is as follows: When the rock drill 96 is in the position shown in Fig. 17, with the feed cylinder 5 in its retracted position and the clamp W5 is set, pressure uid may be supplied to the rear end of the feed cylinder 86 to effect forward feeding movement of the feed piston di to adjust the rock drill with respect to the work. When the rock drill is in operative drilling position, the clamp |03 may be tightened to hold the feed piston 81 in its adjusted position. The clamp it may then be release-d and the valves itil? and i il i? turned into a position to supply pressure fluid to the forward end of the bore of the cylinder 95 to effect forward feed of the rock drill downwardly along the column 82. If desire-d, both of the clamps H15 and |03 may be released and the valves 967 and H9 moved into a position to supply pressure uid simultaneously to the forward end of the bore of the cylinder 5 and the rear end of the bore of the cylinder to effect feeding movement of the piston 81 relative to the cylinder 8E and of the cylinder Q5 relative to the piston ill. The clamp IUI may be tightened by the adjusting bolt H12 to secure the rock drill in its raised position with respect to the column 82, thereby to prevent forward movement of the rock drill downwardly with respect to the column due to leakage of pressure fluid past the pistons when the supply of pressure fluid to the feed cylinders is cut off. By removing the bolt 85 from the perforated lug 83, the column t2 may be rotated about its longitudinal axis relative to the supporting frame 'i5 to move the rock drill into any desired drilling position about the longitudinal axis of the column, the holes i being provided for locking the column in its adjusted position. The reversing valve H9 may be operated at will independently of the throttle valve li to effect reversal of the feed and to regulate the rate of feed.

As a result of this invention, it will be noted that an improved rock drill feeding mechanism is provided having an improved compact feeding arrangement whereby a relatively long range of feeding travel of the rock drill is attained. It will further be noted that by providing a plurality of feeding motors, it is possible to use one motor as the adjusting motor to adjust the rock drill and fee-ding motor with respect to the work prior to the feeding operation, it thereafter being possible to clamp the adjusting motor in its adjusted position. It will further be evident that by providing the improved guiding means associated with the feeding and adjusting motors, it is possible to guide the rock drill in an improved manner during the feeding operations. Other uses and advantages of the improved feeding mechanism will be clearly apparent to those skilled in the art.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be further modied and embodied in Various other forms without departing from its spirit or the scope of the appended claims.

What claim as new and desire to secure by Letters Patent is:

l. In a rock drilling mechanism, a support presenting a guideway, a rock drill guided for movement along said support guideway, a feeding motor for feeding the rock drill along the support guideway, and a feeding motor for moving said first mentioned feeding motor and rock drill into adjusted position with respect to the work prior to the feeding operation of said first mentioned feeding motor, said feeding motors having motive medium supply-controlling means including means for limiting motive medium delivery to one of the same exclusively.

2. In a rock drilling mechanism, a support presenting a guideway, a rock drill guided for movement along said guideway, a feeding motor for feeding the rock drill along the support guideway, and a feeding motor arranged in offset parallel relation with respect to said rst mentioned feeding motor for feeding the latter and the rock drill along the support guideway prior to the operation of said first mentioned feeding motor.

3. In a rock drilling mechanism, a support presenting a guideway, a rock drill guided for movement along said guideway, a feeding motor for feeding the rock drill along the support guideway, and a feeding motor arranged in offset parallel relation with respect to said first mentioned feeding motor and adapted to coact with the latter in the feeding of the rock drill along the support guideway.

4. In a rock drilling mechanism, a support providing guiding means, a rock drill mounted on said support for feeding movement along said guiding means, a pair of sequentially operable feeding motors supported on said support and arranged in offset parallel relation to each other for feeding the rock drill along said guiding means, and means for effecting sequential operation of said feeding motors.

5. In a rock drilling mechanism, a support providing guiding means, a rock drill mounted on said support for feeding movement along said guiding means, a pair of sequentially operable feeding motors supported on said support and arranged in offset parallel relation to each other for feeding the rock drill along said guiding means, said feeding motors each comprising a feed cylinder containing a feed piston, and means for effecting sequential operation of said feeding motors.

6. In a rook drilling mechanism, a rock drill, and means for feeding the rock drill comprising a feed cylinder containing a feed piston, a second feed cylinder on which said first mentioned feed cylinder is supported for guided movement during the feeding operation, said second feed cylinder providing,`for the said guiding of said rst cylinder, longitudinally extending guiding means to the rear of its own forward end and likewise containing a feed piston, and said feed cylinders and pistons cooperating to effect feed of the rock drill.

7. In a rock drilling mechanism, a rock drill, and means for feeding the rock drill including a pair of alined feeding motors cooperating to effect drill feed, and a third motor for adjusting said pair of alined feeding motors and the rock drill with respect to the work prior to the feeding operation of said aligned feeding motors.

8. In a rock drilling mechanism, a rock drill, and means for feeding the rock drill including a pair of alined feeding motors, a third feeding motor arranged in parallel offset relation with respect to said alined feeding motors, said motors cooperating to effect drill feed.

9. In a rock drilling mechanism, a rock drill, a column presenting a guideway along which the rock drill is guided, a feed cylinder contained in said column, a feed piston reciprocable in said feed cylinder, a feed cylinder parallel with said column and to which the rock drill is connected, a feed piston contained in said last mentioned feed cylinder, and means for connecting said feed pistons together.

10. In a rock drilling mechanism, a rock drill, a pair of alined feed cylinders, pistons contained in said feed cylinders respectively, a common piston rod connecting said feed pistons together, means for connecting the rock drill to one of said alined feed cylinders, a third Vfeed cylinder arranged in parallel offset relation with respect to said alined feed cylinders, and a feed piston contained in said parallel feed cylinder and connected to the other of said alined feed cylinders.

l1. In a rock drilling mechanism, a rock drill,

a pair of alined feed cylinders, pistons contained in said feed cylinders respectively, a common piston rod connecting said feed pistons together, means for connecting the rock drill to one of said alined feed cylinders, a third feed cylinder arranged in parallel offset relation with respect to said alined feed cylinders, a feed piston contained in said parallel feed cylinder and connected to the other of said alined feed cylinders, and guiding means connected to said feed cylinder to Which the rock drill is connected and slidably mounted in guideways on said parallel feed cylinder.

12. In a rock drilling mechanism, a rock drill, a pair of alined feed cylinders, pistons contained in said feed cylinders respectively, a common piston rod connecting said feed pistons together, means for connecting the rock drill to one of said alined feed cylinders, a third feed cylinder arranged in parallel offset relation with respect to said alined feed cylinders, a feed piston contained in said parallel feed cylinder and connected to the other of said alined feed cylinders, guiding means connected to said feed cylinder to which the rock drill is connected and slidably mounted in guideways on said parallel feed cylinder, and guides on said other alined feed cylinder slidably mounted on said guiding means.

13. In a rock drilling mechanism, a rock drill, a pair of alined feed cylinders, pistons contained in said feed cylinders respectively, a common piston rod connecting said feed pistons together, means for connecting the rock drill to one of said alined feed cylinders, a third feed cylinder arranged in parallel offset relation with respect to said alined feed cylinders, a feed piston contained in said parallel feed cylinder and connected to the other of said alined feed cylinders, and a pair of parallel guide rods secured to said alined feed cylinder to which the rock drill is connected, and guideways on said parallel feed cylinder in which said rods are slidably guided.

14. In a rock drilling mechanism, a rock drill, a pair of alined feed cylinders, pistons contained in said feed cylinders respectively, a common piston rod connecting said feed pistons together, means for connecting the rock drill to one of said alined feed cylinders, a third feed cylinder arranged in parallel offset relation with respect to said alined feed cylinders, a feed piston contained in said parallel feed cylinder and connected to the other of said alined feed cylinders, a pair of parallel guide rods secured to said alined feed cylinder on which the rock drill is mounted, guideways on said parallel feed cylinder in which said rods are slidably guided, and guides on said other alined feed cylinder slidably mounted on said rods.

15. In a rock drilling mechanism, a rock drill, a pair of alined feed cylinders, one reciprocable with respect to the other, feed pistons contained in said feed cylinders respectively, a common piston rod connecting said feed pistons together, means for mounting the rock drill on the reciprocable alined feed cylinder, a parallel feed cylinder, and a feed piston contained in said parallel feed cylinder and connected to said other alined feed cylinder.

16. In a rock drilling mechanism, a rock drill, a pair of alined feed cylinders, one reciprocable with respect to the other, feed pistons contained in said feed cylinders respectively, a common piston rod connecting said feed pistons together, means for mounting the rock drill on the reciprocable alined feed cylinder, a parallel feed cylinder, a feed piston contained in said parallel feed cylinder and connected to said other alined feed cylinder, and means for clamping said last mentioned feed piston in adjusted position with respect to said parallel feed cylinder.

17. In a rock drilling mechanism, a support presenting a longitudinal guideway, a rock drill guided for movement along said support guide- Way, feeding motors acting cumulatively for feeding the rock drill along the sup-port guideway, means for effecting cumulative operation of said feeding motors, and a motor for moving said feeding motors and rock drill into adjusted position with respect to the Work prior to the feeding operation of said feeding motors.

18. In a rock drilling mechanism, a rock drill, motor operated means for feeding the rock drill, and motor operated means for adjusting the rock drill and said feeding means with respect to the Work prior to the feeding operation of said feeding means, said motor operated means having controlling means including means for precluding operation of said feeding means during operation of said adjusting means.

19. In a rock drilling mechanism, a rock drill, motor operated means for feeding the rock drill comprising a pair of cooperating feeding motors acting cumulatively to effect drill feed, means for effecting cumulative operation of said feeding motors, and motor operated means for adjusting the rock drill and said feeding means With respect to the Work prior to the feeding operation of said feeding means.

20. In a rock drilling mechanism, a rock drill, a pair of alined feeding motors each comprising relatively reciprocable cylinder and piston elements, said motors acting sequentially to effect drill feed, means for effecting sequential operation of said motors, means for connecting the rock drill to one of said feeding elements, and a third motor comprising relatively reciprocable cylinder and piston elements coacting with said alined feeding motors, and means for connecting one of said cylinder and piston elements of said last mentioned motor to another element of said alined feeding motors from that to Which said rock drill is connected.

21. In a rock drilling mechanism, a rock drill, a pair of alined feeding motors each comprising relatively reciprocable cylinder and piston elements, said motors acting sequentially to effect drill feed, means for effecting sequential operation of said motors, means for connecting the rock drill to one of said feeding elements, and.`

a third motor arranged in parallel offset relation and comprising relatively reciprocable cylinder and piston elements coacting with said alined feeding motors, and means for connecting one of said cylinder and piston elements of said last mentioned motor to another element of said alined feeding motors from that to which said rock drill is connected.

22. In a rock drilling mechanism, a rock drill, a pair of alined feeding motors each comprising relatively reciprocable cylinder and piston elements, said motors acting sequentially to effect drill feed, means for effecting sequential operation of said motors, means for connecting the rock drill to one of said feeding elements, and a third motor comprising relatively reciprocable cylinder and piston elements coacting With said alined feeding motors, means for connecting one of said cylinder and piston elements of said last mentioned motor to another element of said alined feeding motors, from that to which said rock drill is connected, and guiding means connected to the feeding element to which the rock drill is connected and slidably mounted in guide- Ways on the cylinder element of said third motor.

23. In a rock drilling mechanism, a support presenting a longitudinal guideway, a rock drill guided for movement along said support guide- Way, pressure fluid actuated means for feeding the rock drill along said support guideway, and pressure fluid actuated means for adjusting said feeding means and the rock drill with respect to the Work prior to the feeding operation of said feeding means, said pressure fluid actuated means having controlling means including means for precluding operation of said feeding means during operation of said adjusting means.

24. In a rock drilling mechanism, a support presenting a longitudinal guideway, a rock drill guided for movement along said support guide- Way, pressure fluid actuated means arranged parallel with the support guidevvay for feeding the rock drill along said support guideway, and pressure fluid actuated means for adjusting said feeding means and the rock drill With respect to the Work prior to the feeding operation of said feeding means, said pressure fluid actuated means having controlling means including means for precluding operation of said feeding means during operation of said adjusting means.

25. In a rock drilling mechanism, a support presenting a longitudinal guideway, a rock drill guided for movement along said support guide- Way, pressure uid actuated means arranged parallel with the support guideway for feeding the rock drill along said support guidevvay, and pressure fluid actuated means also arranged parallel with the support guideway for adjusting said feeding means and the rock drill with respect to the Work prior to the feeding operation of said feeding means, said pressure fluid actuated means having controlling means including means for precluding operation of said feeding means during operation of said adjusting means.

ELM'ER G. GARTIN. 

